title: Reduced cerebrovascular reactivity in posterior cerebral arteries in patients with primary open-angle glaucoma.
abstract: OBJECTIVE
  To evaluate the hemodynamics and vasoreactivity in the posterior cerebral artery (PCA) in patients with primary open-angle glaucoma (POAG).
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Thirteen POAG patients (age range, 40-60 years) with marked visual field loss (mean deviation [MD], <-6 dB); a preserved, mostly normal, central visual field of at least 5°; and best-corrected visual acuity of at least 20/40 formed the study group. Exclusion criterion was presence or history of any systemic disorder including cardiovascular diseases. The control group consisted of 12 healthy subjects matched for age and sex with the study group.
  
  
  METHODS
  Applying transcranial Doppler sonography, we measured hemodynamic parameters in both PCAs at baseline, under monocular reversing checkerboard stimulation, and under hyperventilation. The eye with more marked visual field loss was selected in glaucoma patients, whereas in controls, the tested eye was chosen randomly. Ipsilateral and contralateral PCA were defined according to the tested eye.
  
  
  METHODS
  Peak systolic velocity (PSV), end-diastolic velocity, mean velocity (MV), MV change percentage (MV%), resistivity index (RI), pulsatility index (PI).
  
  
  RESULTS
  At baseline, RI (0.55 ± 0.04 vs. 0.52 ± 0.03; P = 0.04) and PI (0.88 ± 0.11 vs. 0.80 ± 0.07; P = 0.04) in the ipsilateral PCA were significantly higher in glaucoma patients than in controls. During checkerboard stimulation, MV% in both PCAs were significantly smaller in the glaucoma group than in controls (19.7 ± 7.2% and 19.0 ± 8.3% vs. 30.7 ± 7.9% and 27.5±9.0%, respectively; P = 0.001 and 0.02, respectively). During hyperventilation, glaucoma patients showed significantly lower MV% in the contralateral PCA than control subjects (-39.8 ± 9.6% versus -47.4 ± 7.0%; P = 0.03). Perimetric pattern standard deviation (PSD) in the tested eye was correlated significantly with RI and PI of the ipsilateral PCA during checkerboard stimulation (P = 0.003, r = -0.76; and P = 0.002, r = -0.76). The MV% of contralateral PCA was correlated inversely with PSD in the fellow eye (P = 0.02, r = -0.64). The difference in MV% between both PCAs was correlated positively with the difference in MD between 2 eyes (P = 0.003, r = 0.75). Under hyperventilation, PSV in the contralateral PCA was correlated negatively with the PSD in the fellow eye (P = 0.03, r = -0.60).
  
  
  CONCLUSIONS
  Vascular insufficiency in the PCAs may be associated with POAG. Changes in the vasoreactivity of PCAs to central visual stimulation may precede marked central visual field loss.
authors.affiliation: Department of Ophthalmology, Peking University Third Hospital, Peking University Health Science Center, Bejing, China; Department of Ophthalmology, The 4th People's Hospital of Shenyang, Shenyang Eye Research Institute, Key Laboratory of Ophthalmology of Shenyang, Shenyang, China.
authors.forename: Shaodan
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Beijing TongRen Eye Center, Beijing TongRen Hospital, Capital Medical University, Beijing, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Xie
authors.affiliation: Department of Vascular Ultrasonagraphy, Beijing Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Vascular Ultrasonagraphy, Beijing Xuanwu Hospital, Capital Medical University, Beijing, China.
authors.forename: Yangshuo
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Department of Ophthalmology, The 4th People's Hospital of Shenyang, Shenyang Eye Research Institute, Key Laboratory of Ophthalmology of Shenyang, Shenyang, China.
authors.forename: Ruoxi
authors.initials: R
authors.lastname: Li
authors.affiliation: Beijing TongRen Eye Center, Beijing TongRen Hospital, Capital Medical University, Beijing, China. Electronic address: wningli@vip.163.com.
authors.forename: Ningli
authors.initials: N
authors.lastname: Wang
authors.affiliation: Department of Ophthalmology, Peking University Third Hospital, Peking University Health Science Center, Bejing, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002561:Cerebrovascular Disorders / Q000503:physiopathology*; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D020769:Posterior Cerebral Artery / Q000503:physiopathology*; D012039:Regional Blood Flow; D014130:Trabeculectomy; D017585:Ultrasonography, Doppler, Transcranial; D014786:Vision Disorders / Q000503:physiopathology; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology
chemical_list: D000959:Antihypertensive Agents